AMSTERDAM — The first time they performed for the Dutch queen, in 2005, Lucas and Arthur Jussen were 12 and 8 years old. The second time, they were 19 and 16.

With bright blue eyes and shaggy blond hair, playing side by side on the same piano, the Jussen brothers have been national figures in the Netherlands since early childhood. They have appeared with international orchestras, including the Hong Kong Philharmonic and the London Chamber Orchestra, and with artists like Ricardo Castro and Lang Lang. They were the first Dutch artists to sign with Deutsche Grammophon, the prestigious classical music label. In many respects, all of that is a prelude.

Now they are finishing their studies, Lucas, 22, at the Escuela Superior de Música Reina Sofía in Madrid, where he is studying with the concert pianist and master teacher Dmitri Bashkirov, and Arthur, 18, at the Conservatory of Amsterdam, where he studies with one of the most prominent Dutch piano teachers, Jan Wijn. Their goal is to move beyond their past as childhood sensations to become adult professionals with full-fledged solo careers.

The brothers are off to a good start. During the 2014-2015 concert season, each of them had their soloist debuts with major orchestras, Lucas at the Rotterdam Philharmonic Orchestra and Arthur at The Hague Philharmonic. This spring, they are together for a tour through the Netherlands with the Amsterdam Sinfonietta. Their touring schedule picks up speed again starting in late May, and in the summer, they will perform at the Concertgebouw, on July 18.

For some musicians with such early success, it might seem obvious to jump directly into full-time music careers, performing wherever invited and, when not on stage, recording albums. But the Jussen brothers, while doing some of this, have turned down invitations to tour so that they can continue training with top masters, reinforcing and expanding their skills.

“When you’re 40 you should be ready to just play concerts,” Lucas said recently by Skype from Madrid. “In the 20s to mid-20s, you really have to take in everything you can while you’re like a sponge. For me it’s still very important to learn and to have someone who keeps us on the right track.”

To maintain a long-term career as a concert pianist requires not only talent, hard work and perseverance but also a “wow” factor, something that makes orchestras and audiences take notice. Both Jussens seem to accept this fact.

“I’m convinced that the audience feels the last 10 percent of what you add to a piece, the part that’s really you,” Lucas said. “If you play a piece in concert exactly the way you’ve planned it out, I believe it can be really good, but I don’t believe it can be amazing. The last 10 percent are the most important 10 percent. It’s the part that pushes a concert from good to incredible.”

Arthur finished secondary school at home in Hilversum last year and is still living with his parents while attending the Amsterdam Conservatory and trying, he said, to be as “normal” a teen as he can be. He has a girlfriend and many teenage friends who don’t like classical music, so they listen to contemporary music he likes: Marvin Gaye, Stevie Wonder and Bruno Mars.

“I do a lot of sports,” he said. “I like to hang out with friends and drink a beer sometimes, just what every kid of my age does. Sometimes I have to say no on a Saturday night, I can’t come, because I have a concert — that’s all.”

Lucas likes to do what other college students do, although he said he missed a lot of parties, flying up to the Netherlands often for concerts. He also has a girlfriend, and he likes to ski and play tennis or soccer.

The brothers’ attitude and work ethic comes from their parents, Paul Jussen and Christianne van Gelder, both professional musicians, who exposed their children to classical music at an early age.

“We are realistic about the world of music, but being realistic and following your heart, you can do those together,” Ms. van Gelder said. “We know, and they know themselves also, that it will be very difficult to find your way in this musical life, because in the first place, there’s less money these days and there are many, many good pianists. So it will not be easy, but they know that.”

Candida Thompson, artistic director of the Amsterdam Sinfonietta, has lived in the Netherlands for 20 years and has watched the brothers grow up in the classical spotlight.

“I knew them as a phenomenon,” Ms. Thompson said. “As a musician, one is a bit cautious because you hear about young talent and you hope very much that they will continue, but sometimes people go at an incredible pace when they’re very young and then suddenly it all stops. You can be dubious about this, and you’re scared for them, almost.”

She is impressed, though, not only with their skills as pianists, but also with their approach to their professional lives.

“They’re now basically up-and-coming young pianists who are being careful with their careers,” Ms. Thompson said. “They’re not overdoing it; they’re performing but not an extreme amount. They’re handling it in a very healthy way. It seems to me they’re on the good path and they love what they’re doing, and that shows.”

Asked if there was ever any sibling rivalry between them, Arthur said: “It’s almost the opposite. If I could choose in a concert whether I play great or Lucas plays great, I’d probably choose that Lucas plays good and I play bad. The situation is almost like that.”

Over the years, they have developed a repertoire of piano works for four hands, including Mozart piano concertos, Beethoven piano sonatas, works for one and two pianos by Francis Poulenc and Ravel, and — one of Lucas’s favorites — Schubert’s Fantasia in F minor, D. 940. These works have been featured on the three recordings they have released.

“We love to play together, but the piano repertoire for duos, for four hands, isn’t as broad and wide as piano solo repertoire,” Lucas said. “If you say, ‘We only want to play together,’ there are so many beautiful pieces you exclude from your piano repertoire.”

What lies ahead may be uncertain, but Lucas said he felt fairly confident about one thing: “We’ll always keep playing together, because we’re very lucky to be born the two of us together, and we love the same thing. It’s not something I think we should stop or throw away very quickly. Sometimes people search a long time for a partner in music.”